Microtome



April 25, 1939.

E. BAuscH ET AL 2,155,523

MICROTOME Filed April 26, 1935 4 Sheets-Sheet l EDWARD BAUSCH GUSTAVEFASSI N INVENTOR ATTORNEY April 25, 1939.

E. BAUSCH ET AL MICROTOME Filed April 26, 1955 4 Sheets-Sheet 3 IOO FIG]

EDWARD BAUSCH GUSTAVE FASSI N INVENTOR ATTORNEY Patented Apr. 25, 1939UNITED STATES PATENT OFFICE MICROTOIHE tion of New York ApplicationApril 26, 1935, Serial No. 18,484

12 Claims.

The present invention relates to microtomes for cutting sections ofmaterials for microscopic examination.

One of the objects of the present invention is to provide a variablefeed microtome which is durable and rugged in construction yet efficientand accurate in operation. Another object is to provide a compactmicrotome having a built-in power drive. A further object is to providea microtome having a reciprocatory carriage and having a linear feedmechanism which does not apply torque to the carriage. Still anotherobject is to provide a new and improved pawl and ratchet feed mechanismfor a microtome in which mechanism the pawl is withdrawn from theratchet during its non-feeding stroke. A further object is to provide anew and improved limiting means for the feed mechanism of a microtome. Afurther object is to provide a new and improved object holder for amicrotome. A still further object is to provide a new and improved knifesupporting clamp for a microtome. These and other objects and advantagesreside in certain novel features of construction, arrangement andcombination of parts as will hereinafter be more fully set forth andpointed out in the appended claims.

In the drawings:

Fig. 1 is a perspective view showing one side of a microtome made inaccordance with this invention.

Fig. 2 is a perspective view showing the other side thereof.

Fig. 3 is a top plan view of the interior mechanism with parts insection.

Fig. 4 is a rear view of the interior mechanism.

Fig. 5 is a side elevation of the interior mechanism with parts insection.

Fig. 6 is a detail view of the pawl and ratchet mechanism in sideelevation.

Fig. 7 is a fragmentary view of same in front elevation.

Fig. 8 is a detail view showing the object holder and clamp in verticalsection.

A preferred embodiment of this invention is illustrated in the drawingswherein ||l indicates the base of a microtome having a feed mechanismhousing indicated generally at and a knife holder indicated generally at|2. The feed mechanism housing II has a front wall l3, two side walls l4and 15 and a cover |6 hinged near the base H] for closing the top andrear.

A shaft |1 mounted in bearings l8 and I9 extends through the side wallI4 and has a fly wheel and an operating handle 2| secured theretooutside of the housing Within the housing,

the shaft I1 is connected by suitable gears 22 and 23 to a shaft 24which is in turn connected to the motor 25 through a suitable one-waydrive indicated generally at 26. An eccentric 21 is secured to the innerend of the shaft H for a purpose to be described later.

The front wall I3 is formed with a vertical slot 28 and a plate 29 ismounted in bearings on each side of the slot 28 for verticalreciprocatory motion. A carriage 30 is secured to the plate 29 extendingrearwardly therefrom in a horizontal direction and has on one side ahorizontal recess 3| in which a block 32 is slidable. This block ispivotally connected to the eccentric 21' so that rotation of the shaft|1 will reciprocate the carriage 30 and the plate 29. Two members 33 and34 are secured to the top of the carriage 30 to form a second horizontalguideway 35. An object holder 36 is slidably mounted in the guideway 35with its axial center passing through the center of the plate 26.

A screw 31 is journalled in bearings 38 and 39 within the carriage 30with its axis parallel to the axis of the object holder 36. The objectholder 36 is provided with an aperture 40 through which the nut 4|extends to engage the screw 31. The top portion 42 of the nut 4| extendsbeyond the aperture 40 and is securely fastened to the object holder 36by bolts 43 and 44. The rear end of the screw 31 is provided with a gear45 for engaging a worm 46 which is fixed to a shaft 41 journalled inbearings 48 and. 49 on the carriage 30. A ratchet 50 is fixed near theouter end of the shaft 41 for receiving power intermittently to drivethe screw 31.

Freely rotatable on the shaft 41 is an arm 5| carrying a pawl 52 forengaging the ratchet 5|]. The pawl 52 is pivoted at 53 on the arm 5| anda spring 54 urges the pawl into engagement with the teeth of the ratchet50. A second arm 55 immediately adjacent the arm 5| is also freelyrotatable on the shaft 41. A pin 56 is secured to the arm 55 and extendsbetween an edge of the arm 5| and a stop 51 on the pawl 52 thus forminga lost motion driving connection between the arms 5| and 55. The pawl 52has a cam portion 58 in the path of the pin 56 so that when the pin 56is moved toward the stop 51, the pawl 52 is pivoted out of engagementwith the ratchet teeth before any rotary movement of the arm 55 istransmitted to the arm 5|. One end of a link 59 is pivoted at 60 to thewall l4 while the other end is pivoted at 6| eccentrically of the arm55. Thus when the carriage 30 is reciprocated by the eccentric 21, thelink 59 will cause the arm 5| and pawl 52 to oscillate and turn theratchet 56.

Adjacent the ratchet 56 on the side opposite the arms 5| and 55, asector shaped pawl lifter 62 is freely rotatable on the shaft 41. Theperipheral edge of the pawl lifter 62 cooperates with a rotatableextension 63 on the pawl 52 to hold the pawl out of engagement with theratchet 56 and by changing the angular position of the pawl lifter 62,the amount of feeding movement imparted by the pawl is changed withoutthe necessity of changing the length of the stroke. Fixed to the pawllifter 62 is a gear 64 which engages a gear 65 on a shaft 66 journalledin a bearing 61 on the carriage 36. The shaft 66 is universallyconnected at 68 to an extensible link 69 which in turn is universallyconnected at 16 to a shaft II leading to the feed setting dial 12.

A gear 13 is fixed on the shaft 41 and meshes with a pinion 14 on ashaft 15 journalled in a bearing 16 on the carriage 36. The shaft 15 isuniversally connected at 11 to an extensible link 18 which isuniversally connected at 19 to a shaft 86 rotatably mounted in the wallI5 and carrying a crank 8|. By means of the crank 8| acting through thegear 13 and pinion 14 the screw 31 can be rotated to return the objectholder 36 from its forward position.

The extent of forward movement of the object holder 36 is limited by ashielding cam 82 pivotally connected at 83 to the carriage 36. As shownin Fig. 6 the left hand side of the shielding cam 82 is movable to aposition where it engages the rotatable extension 63 on the pawl 52 tohold the pawl 52 out of engagement with the teeth of the ratchet 56throughout its entire stroke. The right hand side of the shielding cam82 is formed with a projection 84. As shown in Fig. 5 the projection 84rests against a stop 85 on the carriage 36 when the shielding cam 82 isin its inoperative position. A trigger 86 is pivotally mounted at 81 ona bracket 88 fixed to the object holder 36, and is normally held in avertical position by a spring 89. As the object holder 36 is fed forwardthe trigger 86 engages the stop 85 and the spring 89 is placed undertension. When the trigger 86 passes over the stop 85, the spring 89snaps the trigger 86 into engagement with the projection 84 and theshielding cam 82 is moved to its shielding position so that even thoughthe motor 25 continues to run and reciprocate the carriage 36, therewill be no feeding of the object holder 36.

The front end of the object holder 36 is an internally threaded hollowsocket 96 in which is seated a hollow spherical cup 9|. A sphericallysurfaced nut 92 engages the inner surface of the cup 9| and is securedby a lock nut 93 to a shaft 94 extending through an aperture 95 in thecup 9|. The shaft 94 terminates in a head 96 having a radial slot 91 anda pin 98 fixed in the object holder 36 holds the head 96 and shaft 94against rotation. A nut 99 threaded in the hollow socket 96 is rotatablycarried on the shaft 94 in engagement with the head 96. The nut 99 isrotatable by a handle I66 which extends through a slot ml in the hollowsocket on the object holder 36. A cover ring I62 serves to protect theinterior of the socket against the entry of dust or dirt through theslot I6 I. The object or specimen to be cut is clamped in the cup 9| bya jaw I63 operated by a thumb screw I64.

The knife holder I 2, which is substantially the same as that describedin U. S. Patent 1,765,283 issued June 17, 1930, to W. L. Patterson andG.

B. Gallasch, has two spaced upright members I65 and I66 rigidlyconnected by a web I61. The upright members I65 and I66 are arcuate ontheir bottom surfaces and rest on the arcuate block I68 which isslidably mounted on the base I6 of the microtome. The center of thisarcuate curve is the cutting edge of the knife. The block I68 can belocked in position on the base I6 by a handle I69 and carries a clampingmember II6 under the control of a handle I I I for locking the knifeholder I2 in desired position. Each of the upright members I65 and I66has an aperture or bore H2 and an adjusting screw 3 extends from theknife clamp into this aperture or bore and terminates in an enlargedhead H4. The enlarged head 4 for adjusting the knife vertically is thusrendered easily accessible. The uprights I 65 and I66 are providedrespectively with rigid shields H5 and 6.

In operation, the dial 12 controlling the pawl lifter 62 is set for thedesired thickness and the motor 25 is started at the desired speed bymeans of the switch 1 and governor H8. The motor drive is transmittedthrough the one-Way drive 26, the shaft 24 and gears 23 and 22 to theeccentric 21 which reciprocates the carriage 36. This reciprocatingmovement causes the pawl 52 to rotate the ratchet 56 intermittently and,though shaft 41, worm 46, wheel 45 and screw 31, to feed the objectholder 36 toward the knife holder I2. When the object holder 36 reachesthe forward limit of its travel, the trigger 66 passes over the stop 85and engages the projection 64 on the shielding cam 82 moving the cam 82to a position where it holds the pawl 52 out of engagement with theratchet 56. The carriage may be retracted by the crank 8| which servesto rotate the screw 31 through the wheel 45, worm 46, shaft 41 and gears13 and 14.

From the foregoing it is apparent that we are able to attain the objectsof our invention and provide a new and improved microtome which isdurable and rugged in operation yet efficient and accurate in operation.

We claim:

1. In a microtome a base, a carriage reciprocably carried by said base,means for reciprocating said carriage, an object support slidablymounted on said carriage, a screw mounted on said carriage for movingsaid object support, a ratchet wheel mounted upon said carriage forrotating said screw, a pawl, an actuating link for said pawl pivotallycarried by said base for actuating said ratchet wheel and means fordisengaging said pawl from said ratchet upon predetermined movement ofsaid object support in one direction.

2. In a microtome a carriage, an object support slidably mounted on saidcarriage, pawl and ratchet means for sliding said object support,shielding means movable to a position where said pawl is held out ofengagement with said ratchet wheel, means mounted upon said objectsupport to move said shielding means into its shielding position upon apredetermined travel of said object support and means on the support forholding the shielding means in shielding position.

3. In a microtome a base, a carriage reciprocably carried by said base,an object holder movably mounted upon said carriage, means including apawl and a ratchet wheel for moving said object holder, shielding meanscarried by said carriage for shielding said ratchet wheel from saidpawl, a trigger carried by said object holder for moving said shieldingmeans into shielding position, and a release for said trigger mounted onsaid carriage whereby said shielding means is moved quickly to itsshielding position upon predetermined relative movement between saidcarriage and said object holder.

4. In a microtome a base, a carriage reciprocably mounted upon saidbase, an object support slidably mounted upon said carriage, a screwcarried by said carriage for moving said object support, a ratchet wheelcarried by said carriage for rotating said screw, a pawl armoscillatably mounted on said carriage concentrically with said ratchetwheel for actuating said ratchet wheel, a pawl carried by said pawl arm,a pawl lifter rotatably mounted on said carriage concentrically withsaid ratchet wheel and means for moving said pawl lifter whereby theextent of rotation of said ratchet wheel may be changed without changingthe extent of the oscillation of said pawl arm.

5. In a microtome having a base, a wall carried by said base, a carriagereciprocably carried by said base, an object holder movably carried bysaid carriage, a screw rotatably mounted on said carriage for movingsaid object holder, a ratchet wheel carried by said carriage foractuating said screw, means independent of said ratchet wheel foractuating said screw, a handle rotatably carried by said wall and meansinterconnecting said handle and said actuating means.

6. In a microtome a casing, a carriage reciprocably carried by saidcasing, mechanism for reciprocating said carriage, an object holderslidably mounted on said carriage, means on said carriage for slidingsaid object holder longitudinally, a ratchet wheel rotatably mounted onsaid carriage for actuating said means, a pawl pivotally carried by saidcarriage for actuating said ratchet wheel, and a link pivotallyconnected to said casing and operatively connected tosaid pawl so thatreciprocation of said carriage actuates said pawl.

'7. In a microtome a casing, a knife holder mounted on said casing,guides mounted on said casing, a carriage reciprocably mounted on saidguides, an object support slidably mounted on said carriage, a screwcarried by said carriage for sliding said object support toward saidknife holder, a ratchet wheel carried by said carriage for rotating saidscrew, an arm pivotally mounted on said carriage coaxially with saidratchet wheel, a pawl mounted on said arm for engaging said ratchetwheel, a link operatively connected eccentrically of said arm and.pivotally connected to said casing, and means for reciprocating saidcarriage.

8. A microtome comprising an object holder adapted to be reciprocated, aknife holder having a cylindrically curved base upon which it is movablymounted, said curved base defining the arc of a cylinder whose axis liesabove said knife holder, said knife holder having a large boretherethrough extending substantially parallel to said cylinder axis,clamping means on said knife holder for securing a knife blade therein,spaced means for leveling said knife blade and for moving same intocoincidence with said cylinder axis, said means extending into saidbore.

9. In a microtome a base, an adjustable knife holder mounted on saidbase, a knife'adiustably carried by said knife holder, guides mounted onsaid base, a carriage reciprocably mounted on said guides, an objectsupport slidably mounted on said carriage, a screw carried by saidcarriage for sliding said object support toward said knife holder, meansfor adjusting said knife holder for varying the cutting angle of saidknife relative to said object support, means for locking said knifeholder in adjusted position, a ratchet wheel carried by said carriagefor rotating said screw, an arm pivotally mounted on said carriagecoaxially with said ratchet wheel, a pawl mounted on said arm forengaging said ratchet wheel, a link operatively connected eccentricallyof said arm and pivotally connected to said base, and means forreciprocating said carriage.

10. A microtome comprising a base, a knife carried by said base, acarriage reciprocably carried by said base, an object support slidablymounted on said carriage for movement toward and from said knife, ascrew operatively connected to said support for moving said supporttoward said knife and a feeding mechanism operatively connected to saidscrew for intermittently rotating said screw, said mechanism comprisinga rotatably mounted ratchet wheel, an arm rotatably mountedsubstantially coaxially with said ratchet wheel, a pawl pivotallymounted upon said arm for feeding engagement with said ratchet wheel,actuating means for oscillating said arm and means interconnecting saidactuating means and said arm for withdrawing said pawl from said ratchetwheel uponv movement in its non-feeding direction.

11. A microtome comprising a base, a knife carried by said base, acarriage reciprocably carried by said base, an object support slidablymounted on said carriage for movement toward and from said knife, ascrew operatively connected to said support for moving said supporttoward said knife and a feeding mechanism operatively connected to saidscrew for intermittently rotating said screw, said mechanism comprisinga rotatably mounted ratchet wheel, an arm pivotally mounted coaxiallywith said wheel, a pawl pivotally mounted on said arm for feedingengagement with said ratchet wheel, a sec-- and arm pivotally mountedcoaxially with said ratchet wheel and said first arm, a lost motionconnection between said arms, cam means between said second arm and saidpawl for withdrawing said pawl from said ratchet wheel during said 10stmotion upon movement in its nonfeeding direction and means foroscillating said second arm.

12. In a microtome, a knife, an object support, means for reciprocatingsaid support, feeding means for moving said support towards said knifein a direction perpendicular to the direction of reciprocation, a motorfor driving both said means, means: for disengaging said feeding means,and means on said support for actuating said disengageing means andholding said disengaging means in disengaging relation, upon apredetermined extent of movement of said support toward said knife.

EDWARD BAU'SCH.

GUSTAVE FASSIN.

